Sub-Terahertz and mmWave Penetration Loss Measurements for Indoor Environments

Abstract

Millimeter-wave (mmWave) and terahertz (THz) spectrum can support significantly higher data rates compared to lower frequency bands and hence are being actively considered for 5G wireless networks and beyond. These bands have high freespace path loss (FSPL) in line-of-sight (LOS) propagation due to their shorter wavelength. Moreover, in non-line-of-sight (NLOS) scenario, these two bands suffer higher penetration loss than lower frequency bands which could seriously affect the network coverage. It is therefore critical to study the NLOS penetration loss introduced by different building materials at mmWave and THz bands, to help establish link budgets for an accurate performance analysis in indoor environments. In this work, we measured the penetration loss and the attenuation of several common constructional materials at mmWave (28 and 39 GHz) and sub-THz (120 and 144 GHz) bands. Measurements were conducted using a channel sounder based on NI PXI platforms. Results show that the penetration loss changes extensively based on the frequency and the material properties, ranging from 0.401 dB for ceiling tile at 28 GHz, to 16.608 dB for plywood at 144 GHz. Ceiling tile has the lowest measured attenuation at 28 GHz, while clear glass has the highest attenuation of 27.633 dB/cm at 144 GHz. As expected, the penetration loss and attenuation increased with frequency for all the tested materials.

Indoor Propagation Measurements with Sekisui Transparent Reflectors at 28/39/120/144 GHz

“…Fig. 5(b) reveals a similar trend as demonstrated in [11]. An interesting and important result is the L Pen.…”

“…Further, the reflection characteristics of the transparent reflector will only be compared against the metal, as it is an ideal reflector; other materials are ignored due to space constraints and we will include in our future work. In this context, we also like to point the reader to our prior work [11] where we have characterized penetration loss alone (and not reflection) for the above-discussed materials except the metal and transparent reflector; a key contribution of this work.…”

“…The antenna system has a maximum linear dimension of 1.080 cm with a far-field of 11.205 cm. For more details consult [11].…”

“…With these in perspective, the main goal of this paper is to investigate the critical wireless propagation characteristics of transparent reflectors. In particular, we characterize the penetration loss (attenuation through the material), a measure signifying the leakiness of a material, and reflection properties of the transparent reflector and evaluate its efficacy against the commonly used indoor material [11]. In terms of the operational frequency, we are primarily interested in the commonly considered mmWave bands of 28 GHz and 39 GHz, and the popular sub-THz bands of 120 GHz and 144 GHz.…”

Outdoor-to-Indoor 28 GHz Wireless Measurements in Manhattan: Path Loss, Environmental Effects, and 90% Coverage

“…In order to understand the specific factors that may impact the path loss for a building, we first group the measurements based on the type of glass. "Traditional" glass, often used in buildings predating the availability of float glass in the 1960s, typically has less than 1 dB loss at 28 GHz [36]. Modern Low-e glass can have losses in excess of 25 dB [37]; Figure 3 shows a measured normal incidence loss of 40 dB from Low-e glass at NWC.…”